[Bacterial granulomatous hepatitis]

The liver may react to different infectious and non- infectious agents, developing granulomatous lesions which characterize granulomatous hepatitis. Granulomas of the liver are circumscribed inflammatory lesions (size from 50 to 300 mm) composed of epithelioid cells, varied numbers of mononuclear cells and eosinophils and multinucleated giant cells. They represent a specialized cell-mediated immune response to a wide variety of etiological factors. A broad spectrum of microorganisms may trigger hepatic granulomas. M. tuberculosis is the more frequent agent (~ 44%). Granulomatous hepatitis is characterized by a febrile illness with systemic signs and symptoms such as fatigue, sweating, shivering, hepatomegaly and/or splenomegaly, abnormalities in serum liver tests (aminotransferase, alkaline phosphatase). Liver biopsy provides diagnostic information in approximately 15-30% of cases, identifying directly the microbial agent with special microbial stains and polymerase chain reaction or finding distinctive microscopic features, suggestive of specific microorganisms. In such cases appropriate therapy is possible. Unfortunately in one third of cases is impossible to reach aetiological diagnosis on histological criteria alone. In these cases a therapeutic attempt with steroids, effective in the idiopathic granulomatous hepatitis, may be useful.